Untitled
unknown
plain_text
a year ago
3.8 kB
9
Indexable
Never
class Program { const int N = 8; static void Main(string[] args) { int count = 0; int[,] board = new int[N, N]; //Initialize the board array to 0 for (int i = 0; i < N; i++) { for (int j = 0; j < N; j++) { board[i, j] = 0; } } //Initialize the pointer array int[] pointer = new int[N]; for (int i = 0; i < N; i++) { pointer[i] = -1; } //Implementation of Back Tracking Algorithm for (int j = 0; ;) { pointer[j]++; //Reset and move one column back if (pointer[j] == N) { board[pointer[j] - 1, j] = 0; pointer[j] = -1; j--; if (j == -1) { Console.WriteLine("all possible solutions to N–Queens problem are done"); break; } } else { board[pointer[j], j] = 1; if (pointer[j] != 0) { board[pointer[j] - 1, j] = 0; } if (SolutionCheck(board)) { j++;//move to next column if (j == N) { j--; count++; Console.WriteLine("Solution" + count.ToString() + ":"); for (int p = 0; p < N; p++) { for (int q = 0; q < N; q++) { Console.Write(board[p, q] + " "); } Console.WriteLine(); } } } } } Console.ReadLine(); } public static bool SolutionCheck(int[,] board) { //Row check for (int i = 0; i < N; i++) { int sum = 0; for (int j = 0; j < N; j++) { sum = sum + board[i, j]; } if (sum > 1) { return false; } } //Main diagonal check //above for (int i = 0, j = N - 2; j >= 0; j--) { int sum = 0; for (int p = i, q = j; q < N; p++, q++) { sum = sum + board[p, q]; } if (sum > 1) { return false; } } //below for (int i = 1, j = 0; i < N - 1; i++) { int sum = 0; for (int p = i, q = j; p < N; p++, q++) { sum = sum + board[p, q]; } if (sum > 1) { return false; } } //Minor diagonal check //above for (int i = 0, j = 1; j < N; j++) { int sum = 0; for (int p = i, q = j; q >= 0; p++, q--) { sum = sum + board[p, q]; } if (sum > 1) { return false; } } //below for (int i = 1, j = N - 1; i < N - 1; i++) { int sum = 0; for (int p = i, q = j; p < N; p++, q--) { sum = sum + board[p, q]; } if (sum > 1) { return false; } } return true; } }